Lifting jack



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I. E. DEARSLEY LIFTING JACK Filed Aug. 14. 1924 Patented Feb. 1,0, 1925.

UNITED STATES IRWIN E. DEARSLEY, OF RACINE, WISCONSIN, ASSIGNORTO'WALKER MANUFACTUR- ING COMPANY, OF RACINE, WISCONSIN, A CORPORATIONOF WISCONSIN.

LIFTING JACK.

Application led August 14, 1924. SeriaIvNo. 732,040.

To aZZ whom it may concem:

Be it known that I, IRWIN E. DEARSLEY, a citizen of the United States,residin at Racine, in the county of Racine and tate of Wisconsin, haveinvented certain new and useful Improvements in Lifting Jacks, of whichthe following is a specification.

-'This invention relates to the class of devices known as lifting jacks,and more particularly to such a device designed to have an exceptionallylong lift in 'proportion to its size and height when in llowered orcollapsed position.

While the uses for such a jack are innumerable, it is especially adaptedfor advantageous use with the oversize or balloon tires now usedextensively on motor vehicles. For this use it is desirable to have ajack which is compact and of small vertical height when lowered, inorder to be placed under the 'low axle or other frame part, when thetires collapse, and capable of a comparatively long lift to elevate thecar above its normal driving height in ordery that the tire may bechanged.

The jack is of that type employing a plurality of screw threaded membersworking one within another and each contributing its share to the totallift of the jack. According t0 the embodiment of'the invention hereshown, the jack comprises a pair of non-rotary screws, one of which isstationary and the other vertically movable to lift the load. A hollowsleeve surrounds the-two screws when the jack is lowered, and hasintegral nuts formed in its two ends to engage the two screwsrespectively. Rotary means mounted in a fixed standard engages the outersurface of the sleeve to rotate same, and at the same time allowsthesleeve to move vertically upon the stationary screw.

The object of the invention is to provide a jack, operating as brieflynoted above and as set forth in more detail.v hereinafter, which issimpleand -compact and capable of lifting heavy -loads withlittleeffort.

Other objects and advantages of the'in- ,vention will be readilyapparent from the following detailed description of one approved forn'1of the apparatus.

In the accompanying drawings:

Fig. 1 is a central vertical section through the jack, takensubstantially on the line 1,-1 of Fig. l3.

tending sleeve member 3. The sleeve 3 may conveniently be made as aseparate unitand secured to the base plate l'vby screws 4. The sleeve 3is exteriorly threaded throughout substantially its entire height. Aninterior screw 5, which supports the load, is' freel movable verticallythrough the sleeve 3. load-supporting cap 6 is rockingly mounted :at theupper end of screw 5, so lthat it may tilt slightly to accommodateitself to a tilting load.

Arather thin hollow metallic sleeve 7 is loosely `mounted betweentheinner screw 5 and the threaded sleeve 3. The tube "(3l hasdiametrically disposed vertical slots 8, in which travel pins orprojections 9 extending from the lower end of the inner screw 5. Lugs 10formed on the lower vend of tube 7 travel up and downin slots or grooves11 cut in the innerN surface of sleeve 3. It will be noted that theinner screw 5 and tube 7 rare locked at all times against relativerotation by the engagement of pins 9 inl slots 8. At the same time thetube 'l' is held against rotation bythe engagement of its lugsA 10 inthe slots -11 in the stationary sleeve 3. yBy this means screw 5 isnever allowed to rotate, although it may be lifted verticallycompletely. out of the threaded sleeve 3.

Fig. 2 is a transverse section through the Y 14 meshing with the innerscrew 5. This sleeve 12 serves as a worm-wheel, and l'for this purposelis provided with a series of `Vertical teeth 15 extending parallelwith'the axis of the sleeve or tube throughout substantially its entirelength. Y The driving worm 16 1s mounted on an to the upper end ofinclined axis, as shown more particularly in Fig. 3, in bearings 17 and18 at the upper` end of bracket 2. An anti-friction thrust bearing 19 isprovided between the worm 16 and the bearing 18, and a socket 20 toaccommodate one end of any suitable form of removable crank handle, issecured the supporting shaft 21 for the worm. i I

With the parts constructed and assembled ,as shown in the drawings, ifthe operating crank is turned continuously in a clockwise direction the'sleeve 12 will be continuously rotated in a counter-clockwise directionas viewed from above. This will cause the sleeve 12 to elevate itselfalong the sta tionaryV screw 3 due to the engagement of the nut 13 inthe sleeve 12 with this screw 3. The sleeve 12 will carry the innerscrew 5 bodily upward therewith. At the same time, since the inner screw5 is held from rotation bythe tube 7, and the nut 14 in the upper end ofsleeve 12 is rotating, the inner screw 5 will be moved upwardly withrelation to the sleeve 12. The total lift of the jack is limited by theengagement of the top of tube 7 with the under side of nut 14, whilepins 9 are engaged with the upper ends of slots 8. It will be noted thatin this. position of the parts the f inner screw 5 is lifted completelyout of the standard 3, although the connecting tube 7 is alwayscompletely housed within the standard 3 and the outer sleeve 12.Rotation of the operating handle in the reverse tion. The straightvertical teeth 15 on the Worm-wheel slide freely up and down through theworm, as sleeve 12 moves vertically, and these straight teeth are moreeconomical to manufacture than the ordinary curved worm-wheel teeth. Theuse of the -combination worm and screw drive for elevating the liftingmember gives a great mechanical advantage, so that extremely heavy`loads may be elevated with comparatively little effort. lThe componentparts of theI jack are simple, substantial and easily assem- Lbled,'=andw en the jack is inllowered positioIn illest compactly one within theother.

" 1.' A lifting jack comprisingl a standard and a lifting member havingscrew-threaded engagement with one another, the lifting member havingucontinuous vertically extending gear teeth on its outer cylindricalsurface, and a driving worm meshing with the vertical gear teeth andmounted on the standardon an inclined axis, so that those portions ofthe worm threads which engage the gear teeth are also verticallyextended.

2.*A lifting jack comprising a standard having an exteriorlyscrew-threaded portion, a lifting member interiorly threaded to engagethis portion and provided on its outer cylindrical surface with a seriesof continuous vertically extending gear-teeth, a driving worm mounted onthe standard on an inclined axis so that those portions of the wormthreads engaging with the gearteeth are also vertically extended, and anattaching member for an upwardly inclined removable handle at the upperend of the worm. i

3. A lifting jackcomprising a standard having a screw-threaded portion,a loadsupporting screw freelymovable longitudinally 'through thestandard. means for holding the screw against rotation, a hollow sleevesurrounding the screw and standard, and interiorly threaded at oppositeends to engage the screw and standard respectively, and driving meansmounted on the standard for rotating the sleeve.

4. A lifting jack comprising a standard having a screw-threaded portion,a loadsupporting screw freely movable longitudinally through thestandard, means for holding the screw against rotation, a hollow sleevesurrounding the screw and standard, and interiorly threaded at oppositeends to engage the screw and standard respectively, the outer'surface ofthe sleeve being provided with longitudinally extending gear teeth, anda driving worm mounted on the standard and engaging the teeth on thesleeve.I I

5. A lifting jack comprising a standard having a screw-threaded portion,a loadsupporting screw freely movable longitudinally through thestandard, means for holding the screw against rotation, a hollow sleevesurrounding the screw and standard, and interiorly threaded at oppositeends to engage the screw and standard respectively tlie outer surface ofthe sleeve being provi ed with'longitudinally extending gear teeth, adriving worm mounted on the standard on an inclined axis and meshingwith the teeth on the sleeve, and an attaching member for a removablehandle at the upper end of the worm.

IRWIN E. DEARSLEY.

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